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Your chance to reenact a key moment in astronomy history!

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  • dfischer@astro.uni-bonn.de
    Early this year there will be an unusually good apparition of asteroid (433) Eros, coming to within 0.18 AU in the coming weeks and reaching 8th magnitude.
    Message 1 of 1 , Jan 1, 2012
      Early this year there will be an unusually good apparition of asteroid
      (433) Eros, coming to within 0.18 AU in the coming weeks and reaching 8th
      magnitude. Such close approaches have been used in the last century - esp.
      in 1900/1 and 1930, according to
      http://www.rasnz.org.nz/MinorP/2012Eros.htm and
      http://en.wikipedia.org/wiki/Astronomical_unit#History - to determine the
      Astronomical Unit with higher precision than was possible from the
      Transits of Venus in the two preceding centuries. So in 2012 we have the
      rare opportunity to reenact *both* historical key methods for determining
      the AU, first with Eros and a few months later with Venus!

      While numerous projects to use the ToV for getting the AU are in
      preparation (as they were in 2004), there is now also the proposal for
      coordinated photographic observations of Eros in January and February:
      sought are image pairs taken at precisely the same moment in different
      countries; see
      http://transitofvenus.nl/wp/2012/01/01/eros-and-the-solar-parallax for
      details. Eros' brightness will peak at 8.6 mag. in late January while the
      initially excellent maximum altitude (elevation) slowly shrinks throughout
      the month for the N hemisphere. Just to get a 'feeling' for the geometry I
      checked pairings between Germany and India (Cologne vs. Delhi):

      Jan. 15 23:00 UTC Germany: 32 degrees vs. India: 67 degrees. 8.9 mag. Leo.
      Jan. 25 23:00 UTC Germany: 29 degrees vs. India: 53 degrees. 8.6 mag. Sex.
      Feb. 5 23:00 UTC Germany: 23 degrees vs. India: 35 degrees. 8.g mag. Sex.

      So it *can* be done - all that's needed are pairs of observers in two
      countries, precise coordination and good weather. If you are capable of
      imaging a 9th magnitude object clearly between the stars or know amateur
      astronomers who are, *please* get involved - and activate all
      international networks! The image pairs obtained this way alone should
      have great didactical value - and perhaps we even learn something new
      about the history of astronomy this way ...

      Daniel Fischer
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